There is much confusion about how a portable air conditioner could be ventless (vent free) without the need for an exhaust hose. Truthful answers is what this website provides to dispel myths created by many ill-informed sales copy writers and even some commercial websites as to why air conditioning units must in fact be vented to the outside and what existing types of cooling devices do not need exhaust hoses or external vents of any kind.

The main focus of this website is on the type of movable cooling device that does not need to have a hot air vent because it does not produce any hot air. That device is the evaporative cooler, or swamp cooler (an example is pictured on the right).

Air Conditioning and Hot Air

One of the first things that surprises people is the fact that AC produces hot air as well as cold when they ask the obvious question, "What is the vent hose for anyway?" In fact most AC devices produce as much if not more hot air than they do cold!

All that heated air must of course be exhausted to the outside of the building or if it was merely mixed with the cold air being produced, the net effect would be an increase in temperature. With fixed or mini-split aircons, that job is performed by the connection through an exterior wall between the inside unit that pumps cold air into the room and the outside unity that contains the powerful fan that expels the hot air to the outside.

With portable units, there is no external unit to perform this function. So to get rid of the hot air they produce, the portable device uses a flexible hose that is either fixed to a window vent or fixture, a wall vent or as is often the case, dangled out the nearest available open window.

Portable Evaporative Coolers

There is a big difference when it comes to the portable evaporative cooler that you'll notice right away in the lack of trailing exhaust hose pipe. They don't need any kind of venting simply because they don't produce any hot air!

The method of chilling the air that is emitted from the unit is very similar to the one we experience when we perspire in the heat and a breeze blows across our skin. It feels cold!

Evaporative (or swamp) coolers use this concept to great advantage in the way that they process the warm room temperature air and make it cold. The inner workings of the unit are very simple when compared to refrigerant AC in that there is only a fan, a water reservoir tank to which a porous membrane is attached and stretched out behind the fan.

Warm air is drawn into the back of the unit by the fan, passing the air through the wet, porous membrane and evaporating the moisture which chills the air that is then blasted out the front!

That's the only mechanism that draws power inside this type of cooling device. And that means it uses only around 1/20th the amount of electricity as a similar capacity AC. That's a huge saving in power (and money)!

The Truth is Revealed!

So now you know what these mythical portable air conditioners that don't need to be vented (vent free) really are. I hope I've explained it clearly enough on this page (and explained it even better in some of the associated articles on this website).

The simple fact is that these portable AC units that don't need venting are not really air conditioners at all... they're evaporative coolers! Isn't it great to know?